What happened
On June 23, 2015, a French-registered Jabiru J430 was performing a flight from Dinslaken to Oehna. The flight was part of a mission to return an Extra 300 aircraft to Oehna, a task that had been delayed by previous weather conditions. After landing in Dinslaken in the late afternoon, the pilot departed at 19:12.
Radar data tracked the aircraft flying toward Porta Westfalica. As the flight progressed, the pilot began following the Weser river upstream, likely attempting to avoid low cloud layers. During this period, the aircraft encountered deteriorating weather, including heavy rain and thunderstorms. The aircraft entered a left-hand turn near the Solling mountains, which transitioned into a tightening spiral. During this maneuver, the aircraft'-s speed increased significantly, and the rate of descent grew. The final radar contact occurred at 20:46, showing the aircraft at 3,800 ft AMSL. The wreckage was discovered later that night, with two fatalities at the scene.
The investigation
The BFU investigation focused on the aircraft's structural integrity, the pilot's decision-making, and the meteorological conditions. Investigators examined the wreckage and found that the wing spars had suffered static breaks, indicating the structure was subjected to abnormal loads.
Technical analysis of the Jabiru J430 revealed several deviations from the kit manufacturer's specifications. Most notably, the elevator was missing its required trim tabs. The investigation also identified unauthorized modifications, including non-standard fuel lines, the use of an unapproved control cable in the tail, and a lack of corrosion protection on the wing struts. Furthermore, the aircraft was being operated with both AVGAS and Mogas, despite manufacturer recommendations for AVGAS only.
Findings
- The primary cause of the accident was the pilot flying into instrument meteorological conditions (IMC), which led to a loss of visual reference and subsequent loss of control.
- The aircraft's structure failed due to an extreme load factor of approximately 8.0 g, caused by an abrupt pull-up maneuver at high speed.
- The absence of elevator trim tabs contributed to the accident, as they would have provided a stabilizing effect and helped prevent excessive speeds and over-control.
- The pilot was under significant mental time pressure to reach the destination before sunset, which influenced the decision to follow a route through worsening weather.
- The pilot lacked the necessary instrument rating required for flight in IMC, and the aircraft was not equipped for such conditions.